This application claims the benefit of the Korean Application No. P2000-79640 filed on Dec. 21, 2000, which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a semiconductor device, and more particularly, to a method for fabricating a capacitor in a semiconductor device.
2. Background of the Related Art
In general, a BLT (Bi4xe2x88x92x, Lax)Ti3O12 thin film has approx. 4 uC/cm2 polarization value when the BLT thin film is oriented in c-axis direction, and approx. 50 uC/cm2 polarization value when the BLT thin film is oriented in a-b-axis direction, i.e., more than 10 times greater.
A related art capacitor is fabricated by forming a lower electrode of a metal, forming a dielectric film on the lower electrode, subjecting to heat treatment in a furnace, and forming an upper electrode. When heat treated thus, most of the dielectric film is oriented in c-axis direction, with exceptional minute regions oriented in other axes.
The foregoing related art method for fabricating a capacitor has a problem in that, since most of the dielectric film is oriented in c-axis direction, with a low intensity of polarization, a contribution of the dielectric film to enhancement of electric performance of the capacitor is poor.
Accordingly, the present invention is directed to a method for fabricating a capacitor in a semiconductor device that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a method for fabricating a capacitor in a semiconductor device, which can enhance electric performances of the capacitor.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, a method for fabricating a capacitor in a semiconductor device includes forming a semiconductor device having a source, a drain, and a gate on a semiconductor substrate, forming an interlayer insulating film having a contact hole exposing the source, forming a conductive layer in the contact hole, forming a lower electrode on the interlayer insulating film, inclusive of the conductive layer, coating an insulating material on the lower electrode for forming a dielectric film, subjecting the insulating material to a first rapid thermal annealing of a first temperature in a chamber, to form nuclei oriented along an a-b axis, subjecting the insulating material to a second rapid thermal annealing at a second temperature higher than the first temperature in the chamber, to grow the nuclei oriented along the a-b axis, to form a dielectric film, and forming an upper electrode on the dielectric film.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.